Lattice

Abstract

The invention relates to medical devices and methods of using them. The devices are prostheses which can be percutaneously deliverable with (or on) an endovascular catheter or via other surgical or other techniques and then expanded. The prostheses are configured to have a lattice resistant to dilation and creep, which is defined by a plurality of openings. The prosthesis may also optionally have a stent disposed proximal to the lattice. In exemplary embodiments, the fluoropolymer is expanded polytetrafluoroethylene. The composite materials exhibit high elongation while substantially retaining the strength properties of the fluoropolymer membrane. In at least one embodiment, the lattice is made of a composite material that includes a least one fluoropolymer membrane including serpentine fibrils and an elastomer. A lattice including a generally tubular member formed of a composite material including a least one fluoropolymer membrane containing serpentine fibrils and an elastomer is also provided.

What is claimed is: 
     
       1. An endovascular prosthesis, comprising:
 a self-expanding stent having a stent unconstrained diameter in a deployed configuration; and 
 a graft having a unitary tubular structure arranged across a length of the stent defining a graft diameter that is less than the stent unconstrained diameter prior to the stent being coupled to the graft, the graft being operable to constrain the self-expanding stent to the graft diameter, wherein the graft is configured to resist further expansion beyond the graft diameter and resist forces tending to collapse the stent when the stent is in the deployed configuration. 
 
     
     
       2. The endovascular prosthesis of  claim 1 , wherein the graft is coupled to a stent inner surface. 
     
     
       3. The endovascular prosthesis of  claim 1 , wherein the graft is coupled to a stent outer surface. 
     
     
       4. The endovascular prosthesis of  claim 1 , wherein the stent unconstrained diameter is at least 1 mm greater than the graft diameter. 
     
     
       5. The endovascular prosthesis of  claim 1 , wherein the stent unconstrained diameter is at least 2 mm greater than the graft diameter. 
     
     
       6. The endovascular prosthesis of  claim 1 , wherein the graft diameter varies along a length of the prosthesis. 
     
     
       7. The endovascular prosthesis of  claim 1 , wherein the stent has an outer stent unconstrained diameter that is oversized with respect to the graft diameter in an amount of 10% to 100%. 
     
     
       8. The endovascular prosthesis of  claim 1 , wherein the stent has an outer stent unconstrained diameter that is oversized with respect to the graft diameter in an amount of between 20% and 70%. 
     
     
       9. The endovascular prosthesis of  claim 1 , wherein the stent has an outer stent unconstrained diameter that is oversized with respect to the graft diameter in an amount of between 30% and 50%. 
     
     
       10. The endovascular prosthesis of  claim 1 , wherein the stent has an outer stent unconstrained diameter of 10 mm, and the graft has an inner graft diameter of 8 mm. 
     
     
       11. An endovascular prosthesis, comprising:
 a self-expanding stent having a stent outer diameter in a deployed configuration; and 
 a graft having a graft outer diameter and coupled to and arranged across a length of the self-expanding stent, the graft being configured to apply an elastic constraining force to the stent to limit the self-expanding stent to the graft outer diameter and to limit further expansion of the self-expanding stent and the graft beyond the graft outer diameter and resist forces tending to collapse the stent when the stent is in the deployed configuration. 
 
     
     
       12. The endovascular prosthesis of  claim 11 , wherein the graft comprises a distensible material and is configured to stretch and recover. 
     
     
       13. The endovascular prosthesis of  claim 11 , wherein the stent outer diameter is greater than the graft outer diameter. 
     
     
       14. The endovascular prosthesis of  claim 11 , wherein the stent outer diameter and the graft outer diameter are approximately equal. 
     
     
       15. The endovascular prosthesis of  claim 11 , wherein the graft outer diameter is approximately 10% to 100% of the stent outer diameter. 
     
     
       16. The endovascular prosthesis of  claim 11 , wherein the self-expanding stent and the graft are configured to resist forces collapsing the self-expanding stent from the graft outer diameter. 
     
     
       17. The endovascular prosthesis of  claim 11 , wherein the graft is attach to the self-expanding stent by at least one of adhering the graft to the self-expanding stent via an adhesive, and holding the graft in place on the self-expanding stent by a friction or an interference fit. 
     
     
       18. An endovascular prosthesis having an insertion configuration with a reduced profile and a reduced diameter and a deployed configuration with an enlarged profile and an enlarged diameter that is greater than the reduced diameter, the endovascular prosthesis comprising:
 a self-expanding stent; and 
 a graft having a tubular shape and coupled to and arranged across a length of the self-expanding stent, the self-expanding stent and the graft being expandable from the reduced profile to the enlarged profile, and the graft being configured to apply an elastic constraining force to the stent to limit the self-expanding stent to the enlarged diameter, and resist forces tending to collapse the stent when the stent is in the deployed configuration, and to limit further expansion of the self-expanding stent and the graft beyond the enlarged diameter in the enlarged profile. 
 
     
     
       19. The endovascular prosthesis of  claim 18 , wherein the self-expanding stent comprises a stent outer diameter in the enlarged profile, and the graft comprises a graft outer diameter in the enlarged profile, and the stent outer diameter and the graft outer diameter are approximately equal. 
     
     
       20. The endovascular prosthesis of  claim 18 , wherein the self-expanding stent comprises a stent outer diameter in the enlarged profile, and the graft comprises a graft outer diameter in the enlarged profile, and the graft outer diameter is approximately 10% to 100% of the stent outer diameter.